Set Appliance State:

Isolate Mains Power to appliance as per TOPs P4
Reconnect electrical connector to the fan assembly (low voltage)
Leave other components disconnected
WARNING! - Mains voltage is expected during test follow
TOPs P4 live testing procedure
Mains Power On

Observation:

Does the display stop operating when the fan assembly has been reconnected?
If the display still operates with the fan assembly connected, isolate mains power as per TOPs P4 each time & reconnect 1 x component at a time re-instating mains power as per TOPs P4 live testing procedure , observe which component causes the display to stop operating, choose appropriate option below as required.